Visualization of soil aggregate structures provides insights into their formation mechanisms induced by litter inputs
Pucetaite, Milda LU ; Persson, Per LU ; Parker, Julia ; Johansson, Ulf LU and Hammer, Edith C. LU
(2025)
In Soil Biology and Biochemistry
202.
- Abstract
Soil aggregation is a dynamic process influenced by physical, chemical and biological factors; however, their individual and combined effect on the formation and turnover of aggregates is not well understood. The aim of this study was to examine incorporation of fresh litter inputs of different physicochemical properties including their carbon-to-nitrogen (C/N) ratio – maize (C/N = 12) and straw (C/N = 103) - into aggregates, de novo formed from mineral soil with or without the presence of microbiota. Using rare-earth element oxides, we labelled structures formed during a four-week incubation with a single litter type and traced their incorporation into newly formed aggregates after mixing them together and incubating for a subsequent... (More)
Soil aggregation is a dynamic process influenced by physical, chemical and biological factors; however, their individual and combined effect on the formation and turnover of aggregates is not well understood. The aim of this study was to examine incorporation of fresh litter inputs of different physicochemical properties including their carbon-to-nitrogen (C/N) ratio – maize (C/N = 12) and straw (C/N = 103) - into aggregates, de novo formed from mineral soil with or without the presence of microbiota. Using rare-earth element oxides, we labelled structures formed during a four-week incubation with a single litter type and traced their incorporation into newly formed aggregates after mixing them together and incubating for a subsequent seven-week period. To visualize them, we used synchrotron-based X-ray fluorescence microspectroscopy, which allowed us to demonstrate that presence of the plant-derived particulate organic matter was the key factor for the aggregate formation. Within the timescale of the experiment, neither microbial abundance nor the community composition had any significant effect. However, the relative increase in straw-associated soil in aggregates larger than 250 μm provided support for our hypothesis regarding impact of carbon-rich organic matter on macroaggregation, likely via promotion of fungal growth and hyphal enmeshing. Phospholipid fatty acid analysis further confirmed relatively higher abundance of fungi in macroaggregates in straw-containing soil. All in all, our study provides insights into the initial stages of aggregate formation following litter additions and development of associated microbial community. The spatial analysis enabled by the X-ray fluorescence microspectroscopy enabled visualization of internal aggregate structures, shedding light on the processes involved, which is not possible with bulk analysis alone.
(Less)
- author
- Pucetaite, Milda
LU
; Persson, Per
LU
; Parker, Julia
; Johansson, Ulf
LU
and Hammer, Edith C.
LU
- organization
- publishing date
- 2025-03
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- C/N ratio, Organic matter, Plant litter, Rare-earth element labelling, Soil aggregates, Synchrotron radiation-based X-ray fluorescence microscopy (SR-μXRF)
- in
- Soil Biology and Biochemistry
- volume
- 202
- article number
- 109686
- publisher
- Elsevier
- external identifiers
-
- scopus:85211974497
- ISSN
- 0038-0717
- DOI
- 10.1016/j.soilbio.2024.109686
- project
- How do microbes “tuck away” carbon? The role of microbes in physical soil organic carbon stabilization
- language
- English
- LU publication?
- yes
- additional info
- Publisher Copyright: © 2024 The Author(s)
- id
- 23b4549a-2c18-4c4e-b65c-2f77015b9f24
- date added to LUP
- 2025-01-08 11:03:40
- date last changed
- 2025-04-04 14:59:33
@article{23b4549a-2c18-4c4e-b65c-2f77015b9f24,
abstract = {{<p>Soil aggregation is a dynamic process influenced by physical, chemical and biological factors; however, their individual and combined effect on the formation and turnover of aggregates is not well understood. The aim of this study was to examine incorporation of fresh litter inputs of different physicochemical properties including their carbon-to-nitrogen (C/N) ratio – maize (C/N = 12) and straw (C/N = 103) - into aggregates, de novo formed from mineral soil with or without the presence of microbiota. Using rare-earth element oxides, we labelled structures formed during a four-week incubation with a single litter type and traced their incorporation into newly formed aggregates after mixing them together and incubating for a subsequent seven-week period. To visualize them, we used synchrotron-based X-ray fluorescence microspectroscopy, which allowed us to demonstrate that presence of the plant-derived particulate organic matter was the key factor for the aggregate formation. Within the timescale of the experiment, neither microbial abundance nor the community composition had any significant effect. However, the relative increase in straw-associated soil in aggregates larger than 250 μm provided support for our hypothesis regarding impact of carbon-rich organic matter on macroaggregation, likely via promotion of fungal growth and hyphal enmeshing. Phospholipid fatty acid analysis further confirmed relatively higher abundance of fungi in macroaggregates in straw-containing soil. All in all, our study provides insights into the initial stages of aggregate formation following litter additions and development of associated microbial community. The spatial analysis enabled by the X-ray fluorescence microspectroscopy enabled visualization of internal aggregate structures, shedding light on the processes involved, which is not possible with bulk analysis alone.</p>}},
author = {{Pucetaite, Milda and Persson, Per and Parker, Julia and Johansson, Ulf and Hammer, Edith C.}},
issn = {{0038-0717}},
keywords = {{C/N ratio; Organic matter; Plant litter; Rare-earth element labelling; Soil aggregates; Synchrotron radiation-based X-ray fluorescence microscopy (SR-μXRF)}},
language = {{eng}},
publisher = {{Elsevier}},
series = {{Soil Biology and Biochemistry}},
title = {{Visualization of soil aggregate structures provides insights into their formation mechanisms induced by litter inputs}},
url = {{http://dx.doi.org/10.1016/j.soilbio.2024.109686}},
doi = {{10.1016/j.soilbio.2024.109686}},
volume = {{202}},
year = {{2025}},
}